低能电子离化He原子(e,2e)反应中的动力学屏蔽  

DYNAMIC SCREENING OF THE (e,2e) PROCESSES FOR LOW ENERGY ELECTRON IMPACT IONIZATION OF HELIUM 

作　　者：张穗萌[1,2,3] 陈长进[1,2,3] 徐克尊 

机构地区：[1]六安师范专科学校物理系 [2]安徽大学物理系 [3]中国科学技术大学近代物理系

出　　处：《物理学报》1999年第3期453-460,共8页Acta Physica Sinica

基　　金：国家自然科学基金;安徽省教育委员会科研基金

摘　　要：在三体索末菲参量修正的基础上，进一步对（ｅ，２ｅ）反应的末态Ｈｅ＋中核外电子的有效屏蔽给出修正．这种修正反映了末态四粒子间的动力学屏蔽．并用修正后的索末菲参量计算了入射能量为５０ｅＶ时，共面不对称几何条件下电子离化Ｈｅ原子的三重微分截面．所得结果与ｃｏｎｖｅｒｇｅｎｔｃｌｏｓｅｃｏｕｐｌｉｎｇ理论结果及最新绝对测量的实验数据进行比较，发现当敲出电子能量为１０ｅＶ时，理论曲线更接近实验数据．Abstract Based on the modified three body Sommerfeld parameters,the effective shield of the residual electron in the final state of He + is further modified for (e,2e) processes. Such a modification represents a dynamic screening of the four bodies in the final state. The triple differential cross sections for electron impact ionization of atomic helium at an incident energy of 50eV in the asymmetric geometry are calculated by use of the modified Sommerfeld parameters.The results were compared with those of the absolute measurements and the only existing theoretical results of the convergent colse coupling method.It was found that the present results give a better description for the experimental data at fixed ejected energy of 10eV.

关 键 词：低能电子离化 氦原子 动力学屏蔽 

分 类 号：O571.424[理学—粒子物理与原子核物理]